To the monographs in this rapidly growing field ( three in English and one each in Dutch, Spanish, and Italian), one in French is now added. It covers the entire subject from its history, physical basis, and instrumentation to its practical value. This account is documented by 223 references. The experience of the French School has been chiefly with the direct-body method of Dock (all the illustrations are of such records) and more recently with the ultra-low-frequency method of Burger. Of special interest are records taken on trained athletes before and after performance, and on jet airplane pilots before and after flight. In the clinic there have been special studies of the effect of pulmonary collapse therapy. Interesting observations have been made on extrasystoles, and the results secured are not always in accord with the usual conceptions. The vector ballistocardiograph is considered briefly. For the most part the position taken by